Don't feel like doing the dishes tonight? Just flash a smile at your wife or girlfriend, and she'll probably do it for you.

A new scientific study finds that smiles do melt women's hearts, after researchers found that a man's grin had the power to make women more obedient.

Spanish researchers analyzed the way women behaved during different interactions with male friends and male co-workers. 

In one experiment, researchers had men play a dominant role by having them hand out instructions. Researchers found that women obeyed the men more when he smiled while delivering the instructions.

Shockingly, the findings held true even when men said a blatantly sexist statement after handing out the instructions.

Researchers at the University of Granada in Spain found that besides being more obedient, women also assumed a more narrow and submissive posture when a man flashed a toothy grin compared to when confronting a man who remained serious.

Researchers conclude that the reason why women are more inclined to obey a smiling man was because of his "perceived warmth".

Body language expert Patti Wood told Prevention that the latest findings are disturbing, but women's behavior could be because women rely on body language more than men to make decisions.

"Even if there's dissonance between what's been said and what his body is doing, women will look to the body," Wood said. "If they see a smile, then the interaction seems more friendly."

Wood said that it's a tricky situation and one that underscores just how subtly sexism can intrude in interactions.

Wood said that this type of situation is most important at work because women need to stand their ground while remaining professional.

To avoid being manipulated by a man's smile, Wood stresses that it is important for women to know what they want before meeting men.

She said that knowing exactly what you want will improve your body language and communication and reduce the number of nervous ticks that will reveal your anxieties and insecurities.

Wood said another thing women should watch out for is to stop avoiding eye contact and to stop smiling more than necessary.

"Smiling can make women seem more subordinate," Wood said. "If you're smiling when giving an important statement, it makes that statement weaker."

She also recommends that women be aware of their own behavior in general and to not just focus on a man's body language.

"Think through the verbal message before you respond," Wood said. "If he says something sexist and you smile or shrink, it means he can get away with it."